Cardiovascular disease (CVD) is responsible for one third of global deaths and is a leading and increasing contributor to the global disease burden. Hypertension is already a highly prevalent risk factor for CVD throughout the industrialised world, and is becoming an increasingly common health problem in many developing countries, particularly in urban societies.
The accurate measurement of blood pressure is the sine qua non for successful management of hypertension. Blood pressure is usually measured using a sphygmomanometer or blood pressure monitor. One of the main factors influencing the accuracy of measurement of blood pressure by a blood pressure monitor is the sensor of pressure, the signal from which is processed and transformed into a measure of blood pressure (for example, in mmHg), which later is used for diagnostics and treatment of most CVD. But with time, as well as under influence of different external factors such as shock to or dropping of the device, temperature changes, ageing of the components, etc, the accuracy of the sensor changes, which causes errors in measurement. One of the main problems is often the dropping of the blood pressure monitor, as the main users of blood pressure monitors are elderly and sick people. That is why blood pressure measurement devices, whether aneroid, mercury, or electronic, and including all home blood pressure measurement devices, must be checked regularly for accuracy.
Calibration is performed by attaching the blood pressure monitor to a highly accurate specialised compressor and checking that the pressure displayed by the blood pressure monitor matches that being generated by the compressor. These compressors are usually maintained by the manufacturers or by specialist companies. The blood pressure monitors are sent away to the companies for calibration. This is expensive and inconvenient; further, the blood pressure monitor may be dropped or damaged during transit back from the calibration company, so that the blood pressure monitor is again inaccurate.
Due to these problems, although all consumer blood pressure monitors are calibrated during manufacture, many are never calibrated again. This of course negatively influences the quality of diagnostics and treatment of millions of users of blood pressure monitors.